DFRobot - Gravity: Water Flow Sensor (1/2") For Arduino

This Gravity Water Flow Sensor brings flow-rate measurement and water-volume tracking to irrigation, appliance monitoring, and DIY metering projects. Based on the YF-S201 design, this 1/2-inch sensor combines a plastic valve body, a magnetic flow rotor, and a Hall-effect sensor to measure liquid flowing through a pipe. The 1–30L/min range suits projects that need more information than a simple water-presence reading. A pulse output lets a microcontroller calculate flow rate and accumulated volume, while the Gravity interface supports convenient connection to an Arduino IO Expansion Shield.

Measure Flow Rate and Total Water Volume

Each liter passing through this water flow sensor generates 450 pulses, turning water movement into countable data. Counting pulses over a measured time interval provides flow rate, while accumulating pulses provides total volume. This Hall-effect measurement approach supports both live flow displays and records of water delivered during a watering cycle. The specified ±5% accuracy applies within 2–30L/min, helping distinguish the supported measurement range from the range covered by the accuracy specification.

Gravity Connection for Arduino Projects

The Gravity interface simplifies connecting this water flow sensor to the Arduino IO Expansion Shield, bringing pipe-flow data into an existing controller project. Rather than requiring an analog voltage-to-flow conversion, the pulse output can be counted through a suitable digital input. This interface makes the sensor a practical addition to irrigation controllers and water-use displays. A separate valve or pump, together with suitable control hardware, can act on the measured flow when automatic water regulation is required.

• Measures liquid flow across a 1-30 L/min range
• Magnetic rotor and Hall-effect sensor generate flow-dependent pulses
• 450 pulses per liter supports flow-rate and total-volume calculation
• ±5% measurement accuracy within 2~30L/min
• Gravity interface compatible with the Arduino IO Expansion Shield

• Inner Diameter: 11 mm
• Outside diameter: 20 mm
• Proof Water Pressure:
• Water Flow Range: 1-30 L/min
• Voltage Range: 3.5~12 V
• Operating Current: 15 mA (DC 5V)
• Insulation Resistance: >100 MΩ
• Accuracy: ±5% (2~30L/min)
• The Output Pulse High Level: >4.7 VDC (DC input voltage 5 V)
• The Output Pulse Low Level:
• Output Pulse Duty Ratio: 50% ± 10%
• Water-flow Formula: 1L = 450 square waves
• Working Humidity Range: 25% ~ 95% RH (no frost)
• Dimension: 62*36*35 mm/2.44*1.37*1.37 inches
• Weight: 52g

Installation and Use

• A 20 mm rifled pipe is recommended by the manufacturer
• Avoid contact with corrosive chemicals
• Install vertically, tilted no more than 5 degrees
• Liquid temperature should be less than 120 C to avoid damage

• Gravity - Water Flow Sensor - 1/2" x1